Continuous flow rotary pump

ABSTRACT

In a rotary pump of the type providing for continuous displacement and flow of a fluid material, said pump includes a housing having an intake port and an outlet, a pair of intermating rotor means disposed for rotation within said housing, and said rotors are in communication with said inlet port and outlet so as to provide for the displacement of said fluid material. An elongated channel is formed communicating with each of the inlet port and the outlet so that as fluid material is drawn into the housing it will be exposed to the helical spacings formed along the length of the rotor means, at their point of intermeshing, and likewise said fluid material will be discharged under the induced pressure that forms along the elongated channel communicating with the outlet of said pump housing.

United States Patent 1191 Baehr CONTINUOUS FLOW ROTARY PUMP [76]Inventor: Samuel J. Baehr, La Prairie, 111.

22 Filed: Mar. 16, 1973 21 Appl. No.: 342,071

[ 1 Feb. 11, 1975 Primary Examiner-C. J. Husar Attorney, Agent, or FirmPaul M. Denk [57] ABSTRACT In a rotary pump of the type providing forcontinuous displacement and flow of a fluid material, said pump includesa housing having an intake port and an outlet, a pair of intermatingrotor means disposed for rotation within said housing, and said rotorsare in communication with said inlet port and outlet so as to providefor the displacement of said fluid material. An elongated channel isformed communicating with each of the inlet port and the outlet so thatas fluid material is drawn into the housing it will be exposed to thehelical spacings formed along the length of the rotor means, at theirpoint of intermeshing, and likewise said fluid material will bedischarged under the induced pressure that forms along the elongatedchannel communicating with the outlet of said pump housing.

11 Claims, 6 Drawing Figures [52] U.S. Cl. 418/201 [51] Int. Cl. F0lc1/16 [58] Field of Search 418/201, 202

[56] References Cited UNlTED STATES PATENTS 1,846,700 2/1932 Ungar418/201 2,159,744 5/1939 Maglott 418/201 2,325,617 8/1943 Lysholm et a1.418/201 2,622,787 12/1952 Nilsson 1 418/202 3,282,495 11/1966 Walls .1418/201 3,306,227 2/1967 Bailey 418/202 1 r 9 7 l l l. i 8 10 l- 77SHEET 1 [IF 3 FIG.2.

PM'ENTEB FEB] 1 I975 SHEET 2 OF 3 FIG. 3.

FIG. 4.

PATENTEUFEBI 1197s SHEET 30F 3 1 CONTINUOUS FLOW ROTARY PUMP BACKGROUNDOF THE INVENTION This invention relates generally to a pump, but moreparticularly pertains to a fluid displacement rotary pump wherein thefluid material is continuously and efficiently transferred under uniformflow with negligible pulsatory effects.

There are a multitude of various types of rotary pumps that areavailable in the prior art, incorporating a variety of combination ofgears that furnish displacement of fluids or other materials. Most ofthese earlier pumps utilize some form of a star wheel of other type oflongitudinally ribbed gears which simply intermesh to provide for aforced transfer of fluid, and particularly in a manner which provides apulsatory type transfer of such fluids. For example, rotary pumps of thetype defined as the Pappenheim type rotary pump and the star-wheelgearedtype rotary pump show early embodiments of the type of pumps utilizinglongitudinally arranged intermeshing gears. Most of these types of pumpsincorporate a simple annular intake port that communicates with one sideof the pump proximate the location of the intermeshing relationshipbetween said pair of gears, while the outlet also comprises a simplepipe type discharge positioned proximate the other side of the pump andoppositely from the intake port. While some of these pumps are effectivein providing displacement of liquids and gases, such as while the ribspacings or grooves of these gears convey the fluid around the innerperiphery of the housing, these segmented quantities offluid are thendischarged from the outlet as separate and distinct discharges whichcreate somewhat of a pulsation or rhythmatic form of flow pattern forthe pump.

The present invention obviates the deficiencies inherent in theaforesaid type of prior art rotary pumps, and improves upon theiroperation through the use of helical formed rotors that communicate withinlet and outlet ports along their entire length so as to provide for anoverlapping and continuous intake of fluid into the pump, andsimultaneously provides continuity of discharge of fluid from the sameseries of the rotor spacings at the same time. Hence, the pulsatoryeffect present in the operation of prior art pumps is eliminated byconstructing the rotary pumps in the manner as will be hereinafterdescribed. It is recognized that helically constructed gears have beenutilized in screw type pumps, but it is not believed that helicallyformed rotors communicating along their length with the intake anddischarge of fluid, has been performed.

It is, therefore, the principal object of this invention to provide adisplacement type rotary pump in which fluid material is continuouslytaken into the pump housing and likewise discharged in a manner whicheliminates any oscillatory pattern in the flow of the fluid material.

Another object of this invention is to provide a rotary pump wherein thehelical rotors, or more particularly their spacings or flutes, provide aconstant multiple intake of fluid material, while providing a multiplesimultaneous discharge of quantities of fluid disposed within a seriesof said spacings of flutes from a single outlet.

Another object of, this invention is to provide a helical rotordisplacement pump which may be driven from a single or dual drive meansdepending upon the viscosity of the material being transferred.

Another object of this invention is to provide a pump wherein itsintermeshing rotor means are provided with multiple ribs or lobes,arranged helically, so that a plurality of said lobes, or moreparticularly there intermediate spacings, are exposed to an elongatedchannel communicating with the intake port to provide a form of multipleand continuous absorption or drawing in of fluid into the rotor meansfor immediate pumping.

An additional object of this invention is to provide a displacement pumpwherein a plurality of the parabolic or conic lobes of the multi-helicalribbed rotor are exposed simultaneously to an elongated channelcommunicating with the outlet so as to provide for a simulta neousdischarge of multiple quantities of fluid out of said pump.

These and other objects will become more apparent to those skilled inthe art upon reviewing the following summary, and upon studying thedescription of the preferred embodiment when viewed with the drawings.

SUMMARY OF THE INVENTION This invention, as previously described,comprises a positive displacement rotary pump of the type designed forinducing transfer of fluid material, and said pump includes a casing orhousing with formed cavities therein communicating with an intake portand an outlet to provide said transfer of the fluid material. The intakeport and the outlet are arranged at approximate opposite sides of saidcasing, and are disposed within the influence and vicinity of theintermeshing between a pair of helical rotors disposed forcontrarotation within said housing cavities, so that fluid may be drawninto the pump due to the pressure decrease caused at the intake portupon rotation of said rotors, and like wise, transferred or induced outof the pump at its outlet due to the pressure build up at this juncture.The unique feature of this invention is the provision of rotor meansthat incorporate helical formed gear like ribs and flutes, the samebeing intermeshed with respect to each other within the pump, andfurther including elongated channels, one communicating with each of theintake port and the outlet, with said channels being arranged parallelwith respect to the disposition of the pair of rotors, and also beinglocated within proximity of the meshing of said rotors. Hence, at anygiven moment during the operation of the pump, a series of the ribs, orlobes, and corresponding flutes will be exposed to the intake channel,while at the same time a series of the same or other ribs or flutesfurther around the circumference of the rotor means will be exposed tothe outlet channel, communicating with the outlet port, so that whilefluid is being drawn into the pump, due to the inducing and creation oflow pressure at this location, said fluid will pervade within thespacings between a series of the rotor ribs, or the rotor flutes, so asto provide for a multiple intake of fluid by said contrarotating rotors,and likewise as the fluid is being discharged from the pump it will becontinuously urged out of the multiplicity of spacings between said ribsor flutes as they become exposed to the elongated channel communicatingwith the outlet port of said pump. Hence, there is continuity in thetransfer of fluid during usage of this pump means, as distinct from thetype of rotary pumps available in the prior art that simply utilizegears having longitudinally oriented ribs that simply displace discretequantities of fluid as each rib bypasses the intake port, and likewiseincrimentally discharges separate quantities of fluid as these gear ribsrotate past the outlet port.

A further novel feature of this invention is that since particularly therotor lobes are designed so that they extend approximately one hundredeighty helical degrees, more or less, around their respective rotorsover their length, it is anticipated that as one end of a particularlobe spacing or flute may be completing exposure to the inlet channelits other end is just becoming exposed to the outlet channel andcreating a pressure that forces fluid transfer out of the pump.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, FIG. 1 discloses anisometric view of the pump housing and external spur gears that aredriven during operation of the rotary pump of this invention;

FIG. 2 provides an end view of the rotary pump disclosed in FIG. 1;

FIG. 3 provides a right side view of the rotary pump shown in FIG. 1;

FIG. 4 provides a side view of the rotor means of this invention beingremoved and separated from their disposition within the pump housingcavities;

FIG. 5 provides a transverse sectional view taken along the lines 55 ofFIG. 3; showing the disposition of the rotor means positioned within thehousing cavities and their relationship with respect to the intake portand channel, in addition to the outlet channel and port; and

FIG. 6 provides a transverse sectional view taken along a similar lineas 55 of FIG. 3, but showing a modification in the design of the intakeport channel.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, and moreparticularly in FIGS. 1 through 3, there is disclosed a casing orhousing 1 for a rotary displacement pump A, having the usual intake 2and outlet 3 disposed approximately along the sides of the housing, withthe entire pump being provided with a base 4 to stabilize it during itsoperational use. As shown, the inlet and outlets may be provided withflanges, as at Sand 6, having the usual apertures provided therethrough,so as to provide means for hermetically sealing other conduits orpipelines thereto upon installation of said rotary pump.

Projecting externally of the casing 1 are a pair of shafts 7 and 8 eachmounting a spur gear 9 and 10, respectively, said gears having the usualgear teeth, as shown, around their periphery, and being intermated toprovide for contrarotation of a pair of rotors disposed within the pumpas will be hereinafter described. See FIG. 4. These gears 9 and 10 aremounted for rotation upon their pair of shafts 7 and 8, as aforesaid,which project and extend outwardly of the casing 1 from their integralconnection with their respective rotors 11 and 12, which are supportedfor intermeshing rotation within said casing. Drive means (not shown)may be provided for rotating either one of the gear 9 and 10, so as tofurnish the form of rotation of the rotors l1 and 12 within said pump aspreviously described. It may also be noted that stub shafts 13 and 14are integrally structured with their respective rotors l1 and 12, andare bearing mounted with respect to the opposite end of the pumphousing. Preferably, these shafts 7 and 8 and 13 and 14 are bearingmounted in a fluid tight seal with respect to their end walls.

Also in FIG. 4, the two rotors 11 and 12 are shown independent andseparated from their usual intermeshed mounting within the casing 1, andsaid rotors are each provided with helical means formed upon theirsurfaces that provides for their mating relationship as when rotatedwithin the casing 1. For example, the upper rotor 11 is provided with aseries of semicircular projecting ribs, or lobes, or other conic shapes,as at 15, (See FIG. 5), and they are designed for close tolerance matingwithin correspondingly shaped flutes 16, in this instance beingsemicircular as shown, formed within the peripheral surface of the rotor12. Each lobe 15 of the rotor 11 is formed as a helix, extendingapproximately 180 spirally around the said rotor and extending from endto end. Likewise, each formed flute 16 provided within the surface ofthe rotor 12 is arranged helically around its periphery to that degreenecessary to provide for its mating relationship with and adjacent lobeas the rotor 11 is revolved, and in practice, it would appear that eachflute 14 is arranged spirally approximately around the surface of therotor 12, from end to end. Obviously the angular degrees of thehelically formed lobes and flutes may vary, although in the preferredembodiment, it has been found that the degrees of spiral previouslydescribed provides an effectively designed mating relationship between arotor 11 and the rotor 12 It should also be commented at that thisjuncture that while the preferred embodiment discloses lobes and flutesformed upon the peripheral surface of the rotors 11 and 12, other shapesfor intermating gearlike means formed upon the surface of intermeshingrotors will operate under the principles of this invention. For example,various other types of parabolic shapes for the lobes 13, and equivalentcavities or flutes 14 may operate under the principle of this inventionto provide an efficient rotary pump, provided that such parabolic shapesare formed helically of their respective rotors. Also, in a modifieddesign, it is likely that the rotor 11 may be designed of slightlygreater diameter than the rotor 12, to insure proper mating of thehelical means formed upon their surfaces.

Of particular significance in this invention is the relationship betweenthe intermating of the rotor means lobes 15 within the flutes 16provided upon and within the respective rotors 11 and 12. As previouslydescribed, the shaft 7 extends from one end of the rotor l 1, throughthe end wall 17 of the pump casing, and has mounted thereon the spurgear 9. Likewise, the shaft 8 correspondingly extends from the end ofthe rotor 12, also through the end wall 17, and has the spur gear 10mounted thereupon. When either the shafts 7 or 8 is driven by means of adrive means (not shown), the meshing ofthe gears 9 and 10 provide forthe contrarotation of their two rotors 11 and 12. Under idealconditions, only the teeth of the spur gears 9 and 10 are in contact intheir intermeshing, whereas there is only a very close tolerancefitting, perhaps only within a thousandth of an inch, althoughpreferably not in contact, of the lobes 15 within their respectiveflutes 16 of the two rotors. In this manner, these two members are inclose enough contact to provide for the desired reduction of pressure onthe intake side of the rotary pump, and the increase of pressure uponthe outlet side of said pump. In this manner, there is no frictionalengagement between the two rotors 11 and 12, and no frictional contactis being effected which can cause their accelerated deterioration. Onthe other hand, and although such may effect a slight decrease in theefficiency of operation of the pump, it is just as likely that no spurgears may be intermeshed upon the ends of the shafts of the two rotors,but rather, one of said shafts 7 or 8 may be driven and the two rotorsl1 and 12 may provide for their own driving engagement by means of aparticular lobe 15 coming into contact within a mating flute 16 toprovide the drive for this displacement pump. it is also shown in FIG. 5that the two rotors 11 and 12 are arranged in close tolerance fittingwithin the cavities 18 and 19 of the casing 1, and said cavities are incommunication so as to allow for the aforesaid mating of the rotors.This close tolerance fitting of the rotors also applies with respect totheir ends which are also maintained a close tolerance relationship withthe interior surfaces of the end walls 17 and 17a, or may even be sealedthereat, as through the use of O-rings, or the like.

In FIG. 5, it can be seen that the intake port 2 communicates with achannel 20 and this channel is rather elongated in length, preferablyextending a corresponding distance within the casing that is equal tothe length of the rotors 11 and 12, although it may be of a shorterlength. Likewise, the outlet 3 also communicates with another formedchannel 21, that is also elongated in design, and extends preferably thelength of the casing cavities 18 and 19. The purpose of these elongatedchannels is to provide for exposure of a series of the lobes 15, ortheir intermediate spacings, in addition to the flutes l6,simultaneously to the intake port of the pump, and due to the helicalformation of said lobes and flutes, intake of fluid by respective rotorswill occur continuously and in an overlapping fashion due to themultiple exposure of the helical flutes and lobes to the quantity offluid drawn into and disposed along the length of the channel 20.Furthermore, as the rotors are contrarotated, as for example, while thetop rotor 11 may be rotating clockwise, and the bottom rotor 12 rotatedcounterclockwise, the fluid being pumped will be continuously exposed tothe elongated channel 21, and its communicating outlet 3, over a seriesof the helical lobes and flutes, so as to provide a continuous andoverlapping of fluid discharge without pulsation, from said pump. Thisis distinct from prior art types of rotary pumps wherein fluid issequentially pumped by longitudinally arranged gears which causes apulsation or incremental discharge of fluid out of an outlet port.

A slight modification in this invention is disclosed in FIG. 6 whereinis shown a more precision design for the intake port 2 communicatingwith a channel 22 which is once again elongated in design, as aforesaid,extending approximately the length of the rotors 11 and 12, but thischannel is disclosed as having a height and depth extending about themidpoint of the rotor 11, in addition to below the midpoint of the rotor12. More specifically, and since it was previously described that thelobes 15 on the rotor 11 are formed helically approximately l80, it canbe seen that the upper reaches 23 of the channel 22 is arranged almostdiametrically opposed to the upper reaches 24 of the channel 21, and inthis relationship, a particular intermediate spacing between a pair ofthe lobes upon a rotor 11 will just become closed against the innersurface 18 of the casing 1, and just shortly thereafter the opposite endof the spacing between the same pair of lobes, which is disposedapproximately l around the rotor, will just open into communication withthe channel 21 to commence to discharge the pressurized fluid from theoutlet 3. in a similar arrangement, the lower reach 25 of the channel 22is disposed approximately diametrically across from the lower reach 26of the channel 21 so that as a particular flute has been charged withfluid and becomes somewhat sealed against the inner surface 19 of thecasing cavity, upon movement for a few more degrees the opposite end ofsaid flute, which is arranged approximately around the rotor 12 probablyabout l40, will just commence to pass the location 26 and enter intoopen communication with the channel 21 for discharging its retainedfluid out of the pump and its outlet.

While seven lobes and nine flutes are shown in the preferred embodimentobviously other numerical quantities oflobes and flutes can be utilizedin the combined rotors of this invention. Also, while the helix of thelobes have been described as extending approximately around the rotorfrom end to end, it is likely that other degrees of turn can beconstructed into the rotors. And in addition, if, for example, less ormore than 180 is used for the spiral arrangement of the lobes, then thereaches 23 and 25 for the mofified intake channel 22 may be variedaccordingly, so as to change the capacity of the pump.

It should be obvious that a variety of fluids may be transferred in thisstyle of a rotary pump, and such fluids may comprise air or other gases,liquids, or the like. The size of the design of the outlet channel 21will depend upon the nature of the fluid being pumped, and where thefluids are more compressible, such as a gas or an air, then the channel21 will be designed at a lesser volume so as to allow for the pump tobuild up sufficient pressure of the gas forced into said chamber 21 andinduce its transfer out of the outlet port 3.

Various modifications in the design of this rotary pump may occur tothose skilled in the art in the light of the foregoing disclosure. Thedescription provided is for the preferred embodiment, and any suchvariations, within the spirit of the principle of this invention andwithin the scope of the appended claims, are intended to be covered bypatent protection. The described embodiment is merely illustrative ofthe overall principle of this invention.

Having thus described the invention what is claimed and desired to besecured by Letters Patent is:

1. In a positive displacement rotary pump of the type designed forinducing continuous transfer of fluid material comprising, a pump casinghaving side and end walls, said casing having a pair of communicatingand parallel cavities formed therein, said casing having an intake portand an outlet port provided upon its approximate opposite sides andopening into said cavities at the location of their communication withinsaid casing, said casing being formed having channels provided upon itsinterior cavity surfaces, one of said channels being in communicationwith the intake port, and the other of said channel being incommunication with the outlet port, said channels being elongated andarranged substantially in parallel with the length of said cavities, apair of parallelly arranged and intermeshing rotor means, one of eachrotor means disposed for close tol erance rotation within each of saidcavities, said rotor means intermeshing at the vicinity of thecommunication between said casing cavities, each rotor means having ashaft extending axially from each of its ends, said shafts being bearingmounted within the end walls of said casing, one of said rotor meansincluding a series of helical ribs formed upon its surface, the other ofsaid rotor means including a series of helical flutes formed upon itssurface, said rotor ribs and flutes being intermeshed, a plurality ofsaid ribs and flutes being simultaneously in communication with eitherthe elongated intake port and outlet port channels for providingpulse-free displacement of fluid materials and the continuous dischargeof multiple quantities of said fluid material along the length of saidrotor means, and at least one of said intermeshed ribs and flutes alwaysbeing simultaneously in communication with both the intake and outletchannels during operation of said rotary pump.

2. The invention of claim 1 wherein said helically arranged ribs andflutes of the rotor means extend approximately 140 to 180 around therotor means, and each further extends from end to end of said rotormeans.

3. The invention of claim 1 and including a drive means connecting toand providing for rotation of said rotor means.

4. The invention of claim 3 and including a pair of intermeshing spurgears, one of each spur gears operatively associated with one of saidrotor means, the operation of said drive means provided forcontrarotation of said spur gears and rotor means for effectingdisplacement of the fluid material.

5. The invention of claim 1 wherein said intake port and outlet aredisposed laterally on opposite sides of said housing and proximate thelocation where said pair of rotor means intermate.

6. The invention of claim 1 wherein said axial shafts are bearingmounted and form a fluid tight seal in the end walls of said casing.

7. The invention of claim 1 wherein the helical ribs are in the form ofprojecting lobes.

8. The invention of claim 7 wherein the rotor lobes and flutes aresemicircular in design.

9. The invention of claim 1 wherein said channels have a lengthapproximating the length of the rotor means.

10. The invention of claim 1 wherein the height of the channel at theintake port has upper and lower reaches disposed approximately 180 fromthe respective upper and lower reaches of the channel communicating withthe outlet.

11. The invention of claim 1 wherein each rib is helically formedapproximately 180 around the rotor means, and each flute is formedhelically approximately around its rotor means.

1. In a positive displacement rotary pump of the type designed forinducing continuous transfer of fluid material comprising, a pump casinghaving side and end walls, said casing having a pair of communicatingand parallel cavities formed therein, said casing having an intake portand an outlet port provided upon its approximate opposite sides andopening into said cavities at the location of their communication withinsaid casing, said casing being formed having channels provided upon itsinterior cavity surfaces, one of said channels being in communicationwith the intake port, and the other of said channel being incommunication with the outlet port, said channels being elongated andarranged substantially in parallel with the length of said cavities, apair of parallelly arranged and intermeshing rotor means, one of eachrotor means disposed for close tolerance rotation within each of saidcavities, said rotor means intermeshing at the vicinity of thecommunication between said casing cavities, each rotor means having ashaft extending axially from each of its ends, said shafts being bearingmounted within the end walls of said casing, one of said rotor meansincluding a series of helical ribs formed upon its surface, the other ofsaid rotor means including a series of helical flutes formed upon itssurface, said rotor ribs and flutes being intermeshed, a plurality ofsaid ribs and flutes being simultaneously in communication with eitherthe elongated intake port and outlet port channels for providingpulse-free displacement of fluid materials and the continuous dischargeof multiple quantities of said fluid material along the length of saidrotor means, and at least one of said intermeshed ribs and flutes alwaysbeing simultaneously in communication with both the intake and outletchannels during operation of said rotary pump.
 2. The invention of claim1 wherein said helically arranged ribs and flutes of the rotor meansextend approximately 140* to 180* around the rotor means, and eachfurther extends from end to end of said rotor means.
 3. The invention ofclaim 1 and including a drive means connecting to and providing forrotation of said rotor means.
 4. The invention of claim 3 and includinga pair of intermeshing spur gears, one of each spur gears operativelyassociated with one of said rotor means, the operation of said drivemeans provided for contrarotation of said spur gears and rotor means foreffecting displacement of the fluid material.
 5. The invention of claim1 wherein said intake port and outlet are disposed laterally on oppositesides of said housing and proximate the location where said pair ofrotor means intermate.
 6. The invention of claim 1 wherein said axialshafts are bearing mounted and form a fluid tight seal in the end wallsof said casing.
 7. The invention of claim 1 wherein the helical ribs arein the form of projecting lobes.
 8. The invention of claim 7 wherein therotor lobes and flutes are semicircular in design.
 9. The invention ofclaim 1 wherein said channels have a length approximating the length ofthe rotor means.
 10. The invention of claim 1 wherein the height of thechannel at the intake port has upper and lower reaches disposedapproximately 180* from the respective upper and lower reaches of thechannel communicating with the outlet.
 11. The invention of claim 1wherein each rib is helically formed approximately 180* around the rotormeans, and each flute is formed helically approximately 140* around itsrotor means.